Method and apparatus for cutting materials



March 3, R R ALLEN METHGD AND APPARATUS FOR CUTTING MATERIALS Filed June 5, 1948 4 Sheets-Sheet 1 j INVENTOR.

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METHOD AND APPARATUS FOR CUTTING MATERIALS Filed June 5, 1948 4 Sheets-Sheet 2 March 3, 1953 R. R. ALLEN METHOD AND APPARATUS FOR CUTTIN G MATERIALS 4 Sheets-Sheet 3 Filed June 5, ,1948

Patented Mar. 3, 1 953 METHOD AND APPARATUS FOR CUTTING MATERIALS Robert R. Allen, Arlington, N. J., assignor to Custom Scientific Instruments, Inc., Arlington, N. J., a corporation of New Jersey Application June 5, 1948, Serial No. 31,257

6 Claims.

My present invention relates to a method and apparatus for cutting various materials, such as foil, filaments and strips, for various purposes, such as obtaining segments of small dimensions or of precise accuracy or both. The invention also comprises certain novel products.

Heretofore articles have been cut either by pressure applied through a sharpened edge which indented and thereby cut through the material, or by a shearing action applying pressure on opposite sides of the article to be cut. This method of cutting distorted the material adjacent the cut. Such distortion is not objectionable for many purposes, but may be objectionable where the material is to be cut into very fine or narrow segments, or where an undistorted, accurate, edge is desired.

My present invention provides a method and apparatus whereby cutting of various materials may be accomplished without distortion and with production of very uniform accurate edges.

In my present invention the cutting is accomplished by the passage of the cutting edge of a blade at a very high speed. The speed at which the cutting edge moves may be in the range from everal hundred feet per second to above 1000 feet per second. For example it may range from 700 or 800 feet per second to 1200 to 1400 feet per second or even greater. At these speeds the cutting action does not depend upon pressure nor upon a shearing action to sever the material, but upon the impact, at these high speeds, of the cutting edge. Consequently there is no perceptible distortion of the cutting edge, such as bent or roughened or indented edges obtained by the application of pressure or shearing force. The invention, therefore, provides products having edges which are sharp and uniform and devoid of abraded or torn efiects even when viewed under a high powered microscope, and even when the material being cut is very thin as, for example, less than 0.001.

In my resent invention the cutting blade is moved at a suitable speed, being mounted on a rotor rotating at a high rate of speed. For example a cutting blade may be mounted to project radially from the edge of a disc rotating at a speed of upwards of 45,000 R. P. M. With a disc of a diameter of about four inches, as described more fully in my co-pending application Ser. No. 743,335, filed April 23, 1947, now Patent No. 2,461,621, this would provide a blade speed of 800 feet per second. Speeds of 60,000 to 70,000 R. P. M. which are readily attainable by the apparatus of my invention, would provide speeds over 1000 feet per second. The rotor may be rotated as high as 120,000 R. P. M. As the speed approaches this amount, however, the danger of breakage by centrifugal force becomes imminent and inasmuch as lower speeds are sufiicient it is preferable to use speeds ranging from 45,000 to 70,000 R. P. M.

The material to be cut may be fed to the blade in a direction transverse to the path of the blade at any desired rate of feed. If a thin sheet of foil i fed in a direction transverse to the path of the blade it will be cut into thin strips. A foil of a thickness of 0.0005 fed into the path of the blades may be cut into filament-like strips of a width of 0.001" or less, having square edges free from irregularities even when viewed under magnification. Foil fed in this direction may be of any length desired. If a strip of material is fed in a direction parallel to the plane of travel of the blades but intersecting their path of travel, it will be cut to provide an accurately formed uniform edge even though the material may be of a resilient nature, such as rubber.

The various features of my invention are illustrated, by way of example, in the accompanying drawings in which Fig. 1 is a plan of the apparatus embodying a preferred form of the invention;

Fig. 2 is a side view of the apparatus shown in Fig. 1;

Fig. 3 is a vertical sectional view taken through the axis of the rotor and of means for feeding a sheet transversely to the direction of travel of the blades;

Fig. 4 is a sectional view taken at right angles to that of Fig. 3 through the sheet feeding mechanism;

Fig. 5 is a part section of a modified form of sheet feeding element;

Fig. 6 is a perspective View on a greatly magnified scaleof a square edged filament cut from foil by the apparatus of Figs. 1 to 5;

Fig. 7 is a sectional view of a modification for feeding a strip, such as a wind shield wiper blade, in a direction parallel to the path of the blade;

Fig. 8 is a modification showing means for feeding a strand or group of filaments transversely through the path of the blades.

Referring more particularly to the embodiment of the invention as shown in Figs. 1-5 inclusive, a rotor [0, Fig. 3 (such as described in my co-pending application Ser. No. 743,335, now Patent No. 2,461,621) is mounted on and between a pair of aligned supporting shafts H and I2 to rotate in a suitable housing I3 which may be mounted on a base I4 on which is also mounted a driving motor I5 for the shaft I I. The housin I3 is formed or built up from a number of accurately fitting elements. These parts comprise a plate l5 resting directly on the base !4 and supporting a central spacing plate I1 and a pair of side walls I8 and I9. A lower feeding and guide element is also mounted on the base I4 and complementary thereto an upper guide plate 2!. Between the two side walls I3 and I9 is a space 22 in which the rotor II] rotates. The space 22 is closed by a cover 23 of heavy construction. The rotor and cutting blade rotate in this space without contact with its walls which, at the high speed of the blade, would be destructive. The foil is out while passing through this space without support.

Mounted in a transverse opening to the walls I8 and I9 are a pair of complementary collars 24 and 25, the inner or closed faces of which are closely spaced from the sides of the rotor ID. The collars 24 and 25 are held in position by stepped flanged rings 26 and 21 secured to the side walls I8 and I9 by screws 28 passing through openings in flanges 29 and 30 of the ring 23 and 21 and threaded into suitable openings in the side walls I8 and I9. The rings 26 and 21 have inwardly extending flanges or shoulders 3i and 32 which abut against the ends of the collars 24 and 25 securing same in position by means of screws 33 and 34. Outwardly axial extensions 35 and 36 of the rings 26 and 21 serve to support the outer raceways 31 and 38 of ball bearings. The raceways 31 and 38 are held in place against shoulders 39 and 40 of the extensions 35 and 36 by means of caps M and 42 respectively which abut the ends of the raceways and are secured to the extensions by means of screws 43 threaded therein.

Inner raceways 44 and 45 of the ball bearings are mounted on reduced extensions 46 and 41 of the shafts I I and I2 and are held against spacing rings 48 and 4'9 abutting shoulders on the respective shafts by suitable retaining means. The retaining means for the raceway 45 comprises a nut 50 screwed onto a reduced end of the extension 41 and secured by a cross pin 5I. The nut 50 is received in a recess in the cap 42. Similarly the raceway 44 is retained by a collar 52 through which the shaft extends and which is in turn held by a pulley 53 which is screwed onto the shaft and retained by a pin '54. A spring retaining means may be mounted between the end of the pulley and the opposite end of the collar 52 to retain the parts against vibration.

The shafts II and I2 are provided with outwardly extending flanges '55 and 55 which abut hubs 51 and 58 of the rotor I0 and are secured thereto by means of screws '59. The inner ends of the shafts extend beyond the flanges 55 and 56 at 6-8 and BI and are received in and tightly fit recesses 62 and E3 in the hubs 51 and 58. In this manner the two shafts l I and I2 are securely mounted in a unitary structure with the rotor I0. Suitable lubricating means are provided for the ball bearings supporting the roller. The centrifugal force of the shaft rotating at high speeds would tend to carry this lubrication into the space 22 in which the rotor rotates. To prevent this transfer or flow of lubricatin fluid labyrinth blocks 64 and 65 are provided on the shafts II and I2 between the ball bearings and the flanges 55 and 56 respectively. These blocks have circular spaced projecting flanges and recesses which are interleaved with corresponding recesses and oppositely projecting flanges on the inner sur- 4 faces of the rings 24 and 25 so that they may rotate freely therein. Consequently lubricant reaching the blocks is thrown outwardly by centrifugal force and cannot reach the rotor I0 or the space 22 but drains back to the oil supply through suitable return drains, not shown.

The shafts II and I2 and rotor I0 are driven from the motor '15 by a belt to the-pulley 53. A suitable guard 66 is provided for the belt and pulley. The motor and transmission are so designed as to give the requisite speed to the shaft and rotor.

A cutting blade 61 is mounted on the rotor I0 to project freely from the periphery thereof, the blade being mounted in a recess in the rotor and retained therein by a clamping plate 68 and a pair of screws 69 as described in my co-pending application Ser. No. 743,335, now Patent No. 2,461,621.

The cutting blade rotates in the recess 22 at the very high speeds impartedby the rotor as, for example, at speeds of 800 feet per second to 1200 feet per second. The material to be cut 'is fed into the path of the blade 61. It will be understood that the rotor I0 and blade '61 are balanced as a unit to avoid vibration.

in the embodiment shown in .Figs. 1-5 inclusive, a thin foil 10 of any suitable metal as, for example, aluminum or aluminum alloy, is drawn from a roll 1I rotatably mounted on suitable'supports 12 on the base I4 and fed between the guides 2Il2I into the path of the blade 61. As shown more particularly in Figs. 3 and l, the guiding surface of the lower guide member 201s of a part cylindrical curvature corresponding to the path of the blade 61, and similarly the lower surface of the guide member 2I is of a -com-ple mentary curvature andis separated therefrom by top plates 13 and 14 secured to the guides by screws 15, Fig. 4, to provide a thin .slot 116 of a substantially semi-cylindrical curvature through which the foil is fed. Preferably the axis of the slot 1 6 is slightly offset laterally :or vertically from the axis of the rotor I0 so that the point of intersection of the foil and blade will move radially during the cutting. The foil is drawn from the roll 1| and into and through the slot 16 by means of a roller :11 approximately tangent to the curvature of the slot 1 8. The roller preferably has a surface of relatively highcoefiicient of friction as, for example, being covered with rubber and, therefore, draws and .pushes the foil through the narrowguideslot 1 6.

The roller 11 is contained in a cylindrical recess in the guide block 20. Itshas trunnions 18 and 19 at its ends which are mounted in ball bearings and B I respectively, journalled in bearing blocks 82 and 83 fitted into the ends of the cylindrical recess containing the roller 11 and secured therein by screws 84. The roller 11 may be retained in the inner raceways of the-bearings 80 and BI by means of nuts 85 and 345. The trunnion 19 extends outwardly through the end of the bearing block 83 and has secured on its free-end a gear wheel 81 which meshes with a worm 88 mounted in a bracket 89 secured to the lower guide member 20 by means of a screw '90. The worm 88 in turn is driven from a motor'S I, Fig. .1, through gear reduction elements 92 and 93. The motor 9| may be a variable speed motor so that the rate of feed of the foil into the path of the cutting blade 61 may be controlled to provide any desired width of out.

For example, if a foil of 0.005" in thickness is to be cut into cuts of 0.0.01" in width .and with the rotor rotating at 1000 R. P. S., the speed of the motor 9! would be such as to drive the foil at the rate of one inch per second, thus providing 1000 strips of foil per second. By varying the speeds of the motors I5 and BI, therefore, as, for example, through a suitable control box 92 and. control knobs 93 and 94, rectangular filaments of any desired dimensions may be obtained. Generally, however, filaments of a thickness up to about 0.008" may be cut on the present apparatus. In order to prevent the accumulation or piling up of filaments in the path of the blade, a duct 95 is provided in the guide block 20 to supply compressed air to blow the filaments out of the path of the blade.

An example of the filaments produced by my present invention is shown in Fig. 6. As shown therein the cross-section of the filaments 9B is rectangular having edges 08 which are smooth and undistorted. The filament may be wavy or kinked, as indicated, and the amount of this kinking may be controlled by the angularity of the cutting edge of the blade. In this way the waviness of the filaments may be adjusted for each purpose as, for example, weaving or felting, or to provide a maximum surface for chemical action, such as oxidation or combustion or for abrasive effects.

To increase the tractive effect of the roller 11 it may be provided with a recess 99 corresponding to the curvature of the guide I6 and thus contact on a small arc of the foil rather than tangentially as in Fig. 4.

It will be understood that in passing from the roll II to and through the guiding slot I6 the foil will assume a semi-cylindrical shape so that the blade passes through one edge of the foil to the other with a true cutting action rather than by transverse shearing.

Instead of passing a material in a direction transverse to the path of the blade, a strip of material as, for example, a windshield Wiper blade, may be passed in a direction parallel to a tangent of the path of the blade so as to trim off an edge of the strip. Such an arrangement is shown in Fig. 7. In this modification the two halves I0 and I9 of the rotor and blad housing are provided with a guide block I00 havin a guiding slot IOI, the edge of which intersects the path of the blade. As the strip passes lengthwise through the guiding slot IOI, with an edge projecting into the path of the blade, a longitudinal cut is made. The strip will be fed through the guide IOI at such a rate of speed that successive cuts will be made lengthwise of the strip so as to provide a smooth edge which, owing to the high speed of the blade, is undistorted and free from waviness or inaccuracies. Cuttings from the strip are received in a slot I02 from which they may be blown or removed by any suitable means. The guiding block IOI may be secured in the housing I8 by means of suitable screws I03.

Instead of feeding a filament transversely across the path of the blade, as in Figs. linclusive, a group or bundle of filaments may be fed transversely and cut into lengths of any selected dimension. For this purpose a guiding tube I00, Fig. 8, is mounted at one side of the path of the blade and a receiving tube I05 at the opposite side. A group of filaments may be fed into the guiding tube I04 by means of a pair of rollers I05 and I01. The filaments are then blown forwardly through the tube by means of air jets I08 and I09 so that they stream forward 6 into the path of the blade; Projector air jets H0 in the ofi-take tube I05 serve to draw the severed filaments free from th path of the blade 61.

The cover 23 is of heavy construction and is preferably provided with a switch controlling the motor I5 which is open to prevent rotation of the switch when the cover is lifted.

The above invention, therefore, provides a novel filamentary material, and also provides a method and apparatus whereby materials, such as strips and filaments and thin sheets, may be cut with great accuracy and without distortion of the edge of the cuttings, such as is obtained by shearing or by the application of pressure to a cutting edge.

Having described my invention, what I claim is:

1. A method of cutting material which comprises feeding a sheet of material in. circular transverse curvature and rotating a cutting blade transversely in the path of said sheet from one side edge of said sheet to the other, said material being unsupported at the plane of cutting.

2. Apparatus for cutting sheet material which comprises a rotor, a cutting blade mounted on said rotor and projecting radially therefrom, a guide slot extending toward but short of contact with the path of said blade and of a transverse partly circular curvature intersecting the path of said blade and a roller having its surface projecting into said guide slot and rotating on an axis transverse to said slot.

3. Apparatus for cutting sheet material which comprises a rotor, a cutting blade mounted on said rotor and projecting radially therefrom, a guide slot extending toward but short of contact with the path of said blade and of a transverse partly circular curvature having its axis offset slightly sidewise of that of said rotor and a roller having its surface projecting into said guide slot and rotating on an axis transverse to said slot, and means to rotate said rotor and said roller at independently controlled speeds.

4. Apparatus for cutting sheet material which comprises a rotor, a cutting blade mounted on said rotor and projecting radially therefrom, a guide slot extending toward but short of contact with the path of said blade and of a transverse partly circular curvature having its axis offset slightly sidewise of that of said rotor and a roller having its surface projecting into said guide slot and rotating on an axis transverse to said slot and air channels projecting across the path of said blades adjacent to said guide slot.

5. Apparatus for cutting sheet material which comprises a rotor, a cutting blade mounted on said rotor and projecting radially therefrom, a guide slot extending toward but short of contact with the path of said blade and of a transverse partly circular curvature having its axis offset slightly sidewise of that of said rotor and a roller having its surface projecting into said guide slot and rotating on an axis transverse to said slot, an enclosure for said rotor and an exhaust opening through said enclosure at the opposite side of said blade path.

6. The apparatus of claim 2 in which said roller has a circular curve conforming to the curvature of said slot.

ROBERT R. ALLEN.

(References on following page) 7 REFERENCES CITED The following references are .of record in the file of this patent:

UNITED STATES {PATENTS Number Name Date .Akim Nov. '24, 19-14 Fidd 1- Oct. 125, "1927 Molins Nov. 29, 1927 Abbott 1 .Dec. '12, I933 Walton Oct. .30, 1934 Arthur e. May 16, 1939 Neil: Oc,t. .15, 19.40

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